Association of Plasma Melatonin Levels With Delirium

Delirium is common complications in postoperative critically ill patients. However the mechanism of postoperative delirium is not well understood.The investigators designed a prospective observational study to investigate the association of perioperative plasma melatonin levels with postoperative delirium and general anesthesia. The investigators included 33 patients required intensive care more than 48 hours after sevoflurane anesthesia in an academic tertiary care hospital. The investigators measured plasma melatonin levels 4 times and assessed postoperative delirium using Confusion Assessment Method for the intensive care unit (CAM-ICU).